Application of fluids and promising materials as advanced inter-pane media in multi-glazing windows for thermal and energy performance improvement: A review

Multi-glazing (including double-glazing) windows have attracted increasing attention in recent years due to their effective performance in saving energy consumption. The common medium between two glass panes is stationary air or inert gas and it could be treated as an extra component in multi-glazing windows. This opens possibilities to apply different fluids and promising filling materials, including airflows, flowing liquids, aerogels and phase change materials (PCMs), as advanced inter-pane media to further enhance window performance and match different requirements in different climates. To facilitate the application and further development of such application technologies, this paper aims to provide a comprehensive review mainly including: application technologies, performance assessment methods and indicators, and performance analysis of different application technologies. Also, a comparison of the energy saving potentials of different advanced inter-pane mediums in different climates is provided. In addition, suggestions for future works are given based on current progress.